I am looking for a specific switch system and though it seems like something that might already exist or not be too hard to set up, I just have no idea how to search for it online.

Basically it would function as a 3PDT switch, but instead of having some sort of selector to select between the 3 positions, I want it to have three separate "buttons." (I would call them switches but that seems confusing)...

So, it would be a group of three ON/OFF pushbuttons wherein each one, when pushed, would turn that area of the circuit ON and the other two OFF.

This is definitely the basic concept of what I was looking for. The specific product on ebay you linked to doesn't mention how many contacts it has so it may not work for me. However, I now know what the name of this type of switch is, which is a great start.

I should have realized that it's the same type of switch that's on, for instance, a cassette player! Knowing that, I may be able to salvage a set that fits my purpose.

Figuring out what kind of switch does this was actually just the first step in figuring out a more complicated project so I may have more questions down the line.

Considering the overall amount of switching that is going to be occurring I have considered using a relay but do not have any experience with them. And it seems a bit complicated/expensive for my purpose.

FYI, I am trying to make a combination mixer/channel switch/automatic crossfader with three separate buttons that :

A) mixes the two (line-level audio) signals to the output when the first button is pushed
B) switches immediately between one signal and the other when the second button is pushed
C) gradually crossfades between one signal and the other when the third button is pushed.

in each case it is the same 2 inputs, and 1 output.

I have made a mixer before, I have made an A/B channel switch before, and I know how I am going to do the crossfade (using vactrols, photoresistors connected to LED's that fade in/out when power to them is switched on or off) but the thing that I am struggling with is the switching (switchery, if you will).

I think I need to make some kind of logic diagram next to help me sort it out, now that I have a clearer idea of what my options are, switch-wise.